Soil Organic Matter and Nutrient Dynamics Following Different Management of Crop Residues at Two Sites in Austria

Abstract Long-term soil organic matter(SOM) and nutrient dynamics following different crop residuemanagement were studied in two field experiments in Austria: in Marchfeld since 1982 and in Alpenvorland since 1986. The turnover of SOM was modeled with the CCB (CANDY carbon balance) model. SOM parameters such as soil organic carbon (SOC), active C (KMnO 4 ), total nitrogen (N t ), and the N-mineralization potential increased significantly following crop residueincorporation. C/N ratios, however, did not differ significantly. Plant-available potassium (K) increased by 40% (Alpenvorland) and 50% (Marchfeld), magnesium (Mg) only in Marchfeld (+ 9.7%), and no effect was evident for phosphorus at either site. Our results showed a strong agreement between measured and simulated SOC values. SOC can be maintained in the long term with the incorporation of crop residues, but it will decrease with annual removal.